Screw-driver.



. R.-B.BENJAI SCREW DRIV APPLICATION FILED JAN. 27, 1910.

1,049, 9 I Patented Jan. 7, 1913.

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REUBEN B. BENJAMIN, or CHICAGO, ILLINOIS, ASSIGNOR "r0 ,BENJAMIN-SELLAR OFFICE.

MFG. 00., or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.-

SCREW-DRIVER.

Specification of Letters Patent.

Patented Jan. 7,1913.

Application filed January 27, 1910. Serial No. 540,411.

the following is a full, clear, concise, and.

exact description, reference being had to the accompanying drawing, forming a part of thls specification.

My invention relates to screw drivers and such other too-ls as are provided with a handle which must be grasped and turned by hand during the use of the tool.

It is the object of my invention to improve tools of this character by rendering them more convenient and comfortable in use, without adding to the cost of the tool to any material extent.

Two embodiments of my invention are illustrated, by way of example, in the accompanying drawings, but other embodiments, within the scope of the appended claims, will readily occur to those skilled in the mechanical arts.

In the drawings: Figure 1 is a perspective view of a screw driver constructed in accordance with my invention; Fig. 2 is a partly sectional elevation of the same showing the palm-piece in its extended condition; and Fig. 3 is a view similar to Fig. 2 but showing the palm-piece in its compressed condition.

Referring now to the drawings the screw driver is provided with a handle 10 of wood or the like having its outer end rounded. An axial depression 11 is formed at the center of the outer end of the handle, for receiving a boss 12 which extends inward from the center of a member 18 which, in the embodiment now referred to, is of hollow, substantially hemispherical, form.

This member will hereafter be termed the palm-piece. In practice the palm-piece 13 is somewhat less than hemispherical in order to avoid the binding eifect which might occur if a completely hemispherical palm-piece were-used. The boss 12 is hollow and is formed with a central aperture through which passes a screw 14, the end of which enters the wood of the handle at the bottom of the depression 11, the head of ,the screw engaging the bottom of the boss extent as to allow a slight play between the palm-piece 13 and the end of the handle 10. (See Fig. 2.) depression 11 and the lower end of the boss 12 of palm-piece is inserted a spring 15, the tendency of which is to hold the palm-piece in its extended condition, a, away from the end of the handle. is shown as being formed of fiber or hard rubber but it may be formed of any suitable material. 7

It will be seen from the above that the Between the bottom of the The palm-piece 13 I palm-piece 13, will be pressed inward to engage frictionally the end of the handle 10, (Fig. 3) during the driving of a screw, so that the whole of the hand may be used in forcing the screw around. When the hand is turned back, however, preparatory to another forward turn, the end thrust of the palm is naturally lessened and the spring 15 can then force the palm-piece 13 out of its frictional engagement with the end of the handle, whereupon the palm-piece can turn I relatively to the handle and remain station ary relatively to the palm of the person using the screw driver. When force must be exerted in order to turn a screw in either direction, it becomes necessary to'press forward wit-l1 the palm with considerable strength upon the outer end of the handle. The end of the screw driver is thus held firmly in the slot of the screw while the latter is being turned in the required direction. Itthen becomes necessary to turn the hand back relatively to the screw driver and the resulting friction causes considerable soreness of the palm, especially when the hand is not hardened and has become moist by the work.

My imprvoed screw driver entirely obviates the above disadvantage by reason of the fact that, while the palm-piece 13 makes a firm frictional engagement with the end of the handle 10 when it is pressed forward against the handle during the turning of the screw, and therefore the whole surface of the handle is utilized, nevertheless, when the hand is turned back relatively to the screw driver, the end pressure necessarily relaxes and the palm-piece is moved out of engagement with the end of the handle and can turn back with the hand. The palmpiece thus never changes its position relatively to the palm of the person using the screw driver, and there is no friction and no soreness. Furthermore, it is not usually necessary to exert much force in driving a screw until the latter portion of the operation. In using my improved screw driver, therefore, it may be held in place in the slot of the screw by a light end pressure during the first part of the insertion of the screw, the pressure being not sufiicient to cause the cap 13 to engage the end of the handle. Thus the screw may be inserted up to a certain point by allowing the palm-piece 13 to remain stationary relatively to the palmpiece while the body of the handle is turned by the fingers. When the resistance of the screw becomes too great a greater end pressure is applied with the result described above. This method of using the screw driver is particularly useful in inserting machine screws which usually enter very readily at first. These effects are obtained by means which do not increase the cost of the screw driver to any marked extent.

The broad invention disclosed herein is claimed as such in my copending application Serial No. 612,793, filed March 7, 191.1. No claim is made herein to any subject-matter which is disclosed in the said copending application.

Having thus fully described my invention, I declare that what I claim is:

1. A hand-tool comprising a blade-carrying member having the end thereof remote from the blade rounded, and a cup-shaped palm-piece mounted upon the rounded end of said handle so as to be rotatably and longitudinally movable into and out of engagement with the rounded end of said handle, for the purposes set forth.

2. A hand-tool comprising a blade-carrying member having the end thereof remote from the blade rounded, and having an axial recess in such rounded end, a hollow substantially hemispherical palm-piece, having an axial inwardly extending projection adapted to enter said recess, and means for securing said projection loosely in said recess, whereby the palm-piece is rotatably mounted on said handle so as to be longitudinally movable into and out of engagement therewith, for the purposes set forth.

3. A hand-tool comprising a. blade-carrying member having the end thereof remote from the blade rounded, and having an axial recess in such rounded end, a hollow substantially hemispherical palmpiece, having an axial inwardly extending projection adapted to enter said recess, means for securing said projection loosely in said recess, whereby the palm-piece is rotatably mounted on said handle so as to be longitudinally movable into and out of engagement therewith, and a compression spring mounted in said recess so as to engage said projection, whereby said palm-piece is normally held out of engagement with said handle, for the purposes set forth.

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

REUBEN B. BENJAMIN. Vitnesses:

CHARLES G. Corn, E. R. KING.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

